Background

Red yeast rice (RYR) is made from yeast (Monascuspurpureus) grown on rice. It is a dietary staple in some Asian countries. Processed red yeast rice supplements include red yeast rice extract (RYRE), which is any extract of red yeast rice, and Xuezhikang, an alcohol extract of red yeast rice.

RYR contains several compounds known as monacolins, which block the production of cholesterol. One of these, monacolin K, has the same structure as the drugs lovastatin and mevinolin. Studies suggest that RYR use may lead to a 10-33% reduction in low-density lipoprotein (LDL, or "bad") cholesterol. This is a moderate effect, compared to the U.S. Food and Drug Administration (FDA)-approved "statin" drugs. Information on the long-term safety of RYR is limited at this time.

RYR extract (RYRE) has been sold in over-the-counter supplements to lower cholesterol, in the form of products such as Cholestin® (Pharmanex, Inc.). However, the formula has been changed. Cholestin® contains many compounds in addition to monacolin K, including other monacolins, starch, fiber, protein, and fatty acids. Research suggests that this product may treat high cholesterol and triglycerides in both humans and animals. Some studies report that RYR use may increase levels of high-density lipoprotein (HDL, or "good") cholesterol. However, information on the effects of monacolin K alone is lacking.

There has been some controversy between Pharmanex, Inc., the FDA, and statin manufacturers as to whether Cholestin® should be considered a drug or a dietary supplement. The U.S. District Court in Utah ruling in March 2001 states that RYRE is an unapproved drug. Thus, the RYRE known as Cholestin® is no longer available in the United States. Other products containing RYRE alone or in combination products may still be commercially available in the United States, primarily through Internet retailers.

Besides RYR's use for high cholesterol, pigments made by Monascus species have been used to color food in Asian cooking. Future uses of RYR may include decreasing heart disease risk and improving the health of people with diabetes.

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Adults (18 years and older)

Red yeast rice (RYR) should be taken with food. A dose of 1,200 milligrams of red yeast powder in the form of capsules has been taken by mouth twice daily with food. In Asia, the average consumption of naturally occurring RYR is 14-55 grams daily.

To treat coronary heart disease, 1,200-2,400 milligrams of Xuezhikang has been taken by mouth daily for 2-12 weeks. Xuezhikang has also been taken by mouth at doses of 0.3-0.6 grams twice daily for 4-4.5 years on average (range: 0.5-7 years). Xuezhikang has been taken by mouth at a dose of 1,200 milligrams daily for 12 weeks to 24 months.

To treat diabetes, two capsules of 300 milligrams of Monascus extract have been taken by mouth for eight weeks.

To treat high cholesterol, 1,200-2,400 milligrams of Cholestin® has been taken by mouth 1-2 times daily for up to 12 weeks. Doses of 600-1,800 milligrams RYR have been taken by mouth up to three times daily for 8-24 weeks. Two capsules of 300 milligrams of RYR product have been taken by mouth daily for 1-3 cycles of eight weeks each. Doses of 600-3,600 milligrams of Xuezhikang/RYR have been taken by mouth 1-2 times daily for up to one year. A dose of 2-4 capsules of Xuezhikang has been taken by mouth twice daily for 8-12 weeks. A dose of five capsules of 0.5 grams of Xuezhikang has been taken by mouth twice daily for two months. Doses of 0.6-3.6 grams of RYR extract have been taken by mouth daily for four weeks to 4.5 years. Doses of 0.6-1.2 grams of Monascus purpureus rice preparation have been taken by mouth 1-2 times daily for eight weeks to one year, with dose adjustment depending on cholesterol levels and tolerance. Five Zhitai capsules have been taken by mouth twice daily (for a dose of five grams daily) for two months. Three Zhibituo tablets (0.35 grams each) have been taken by mouth three times daily for a total of 3.15 grams daily. One to two capsules of Xuezhikang have been taken by mouth 2-3 times daily for up to 24 weeks. Four capsules of RYR (HypoCol®, Wearnes Biotech & Medicals Pte, Singapore) have been taken by mouth daily for 16 weeks.

To treat fatty liver, 0.6 grams of RYR have been taken by mouth twice daily for 12 weeks.

Children (younger than 18 years)

There is no proven safe or effective dose for RYR in children.

Evidence

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

High cholesterol

Monacolins, compounds found in red yeast rice extract (RYRE), have been found to have health benefits since the early 1980s. In particular, monacolin K has been marketed as lovastatin and mevinolin. However, due to the large number of compounds that may lower cholesterol other than monacolin K, the cholesterol-lowering mechanism is still unclear. It has been suggested that RYR may block absorption of cholesterol, promote the clearance of cholesterol, or exert antioxidant effects. Overall, results suggest that red yeast rice (RYR) products may lower levels of total and LDL cholesterol in people with high cholesterol. Some studies also suggest increases in HDL cholesterol. More information on long-term safety and effectiveness is needed.

C

Coronary heart disease

Human studies suggest that RYR use may improve blood flow through widened vessels and reduced inflammation. However, further research is needed in order to determine the effect of RYR on heart disease symptoms and mortality.

C

Diabetes

Although it has not been well studied in humans, RYR has been found to reduce blood sugar and increase insulin in animal research. Early human studies also suggest that RYR may have benefits in diabetes. Further research is needed before firm conclusions can be made.

C

Fatty liver

Early evidence suggests that RYR may benefit liver health in people who have diabetes. However, more studies are needed before conclusions can be made.

Uses based on tradition or theory

The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Interactions

Interactions with Drugs

Red yeast rice (RYR) may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants (blood thinners) such as warfarin (Coumadin®) or heparin, antiplatelet drugs such as clopidogrel (Plavix®), and nonsteroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®).

RYR may affect blood sugar levels. Caution is advised when using medications that may also affect blood sugar. People taking drugs for diabetes by mouth or insulin should be monitored closely by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.

RYR may interfere with the way the body processes certain drugs using the liver's cytochrome P450 enzyme system. As a result, the levels of these drugs may be increased in the blood and may cause increased effects or potentially serious adverse reactions. People using any medications should check the package insert and speak with a qualified healthcare professional, including a pharmacist, about possible interactions.

Interactions with Herbs and Dietary Supplements

RYR may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba, and fewer cases with garlic and saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases.

RYR may affect blood sugar levels. Caution is advised when using herbs or supplements that may also affect blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment.

RYR may cause low blood pressure. Caution is advised in people taking herbs or supplements that lower blood pressure.

RYR may interfere with the way the body processes certain herbs or supplements using the liver's cytochrome P450 enzyme system. As a result, the levels of other herbs or supplements may become too high in the blood. It may also alter the effects that other herbs or supplements possibly have on the P450 system.

RYR may also interact with antibacterials, anticancer herbs and supplements, antifungal herbs and supplements, anti-inflammatory herbs and supplements, antioxidants, astaxanthin, cardiac glycosides, cholesterol-lowering herbs and supplements, coenzyme Q10, grapefruit, herbs and supplements that may affect the immune system, herbs and supplements that may affect the nervous system, herbs and supplements that may harm the liver, herbs and supplements that may treat heart disorders, herbs and supplements that may treat stomach disorders, iron, milk thistle, niacin, octacosanol, St. John's wort, tannin-containing herbs and supplements, thyroid herbs and supplements, vitamin A, and zinc.

Methodology

This information is based on a systematic review of scientific literature and was peer-reviewed and edited by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Note: Monacolin K, a compound found in red yeast rice, has the same structure as the drugs lovastatin and mevinolin. This bottom line covers Monascuspurpureus, excluding details about related species.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

Avoid if allergic or sensitive to rice, red yeast, its parts, or members of the yeast family (Monascaceae).

Side Effects and Warnings

There is a lack of data on side effects associated with red yeast rice extract (RYRE). In general, side effects and interactions for RYRE may be similar to those of low-dose "statin" drugs, since monacolin K is the same chemical compound as lovastatin. Side effect frequency appears to be low with moderate consumption. Long-term safety data are lacking.

Mycotoxin citrinin, a compound made by Monascus species, may pose a health threat. High doses have been found to be harmful in animal research. There is no established limit in humans, and caution should be used when consuming products containing citrinin.

Red yeast rice (RYR) is likely safe when used as a condiment in food.

RYR is possibly safe when taken by mouth to lower cholesterol in doses of up to 2.4 grams daily for up to 12 weeks.

Use cautiously in doses higher than 2.4 grams daily for longer than 12 weeks.

Use cautiously in people who have skin disorders. Rash has been reported with RYR use.

Use cautiously in people who have abnormal liver function tests or liver disorders, or those using alcohol or agents that may be toxic to the liver. RYR may affect liver function.

Use cautiously in people who have kidney problems. RYR may be harmful to the kidneys.

Use cautiously in people who have stomach problems. RYR may worsen symptoms such as gas, heartburn, inflammatory bowel disease, and nausea.

Use cautiously in people who tend to have dizziness. RYR may cause dizziness.

Use cautiously in people who have low levels of coenzyme Q10 (CoQ10). RYR may further decrease CoQ10 levels.

Use cautiously in people who have headaches. RYR may cause headaches.

Use cautiously in people who have musculoskeletal disorders or those taking cyclosporine, cytochrome P450-3A blocking agents, or macrolide antibiotics. RYR may increase the risk of muscle disease, muscle fiber breakdown, and muscle pain.

RYR may affect blood sugar levels. Caution is advised in people with diabetes or low blood sugar and in those taking drugs, herbs, or supplements that affect blood sugar. Blood sugar levels may need to be monitored by a qualified healthcare professional, including a pharmacist, and medication adjustments may be necessary.

Use cautiously in people who have low iron levels. RYR may affect hemoglobin.

Use cautiously in people who have a weakened immune system or those taking agents that may weaken the immune system. Use cautiously in people who are undergoing surgery or an organ transplant. RYR may weaken the immune system.

Use cautiously in people who have nerve damage. RYR may increase the risk of nerve damage.

RYR may affect the risk of bleeding. Caution is advised in people with bleeding disorders or those taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary.

RYR may cause low blood pressure. Caution is advised in people taking drugs or herbs and supplements that lower blood pressure.

Use cautiously in people taking cardiac glycosides. RYR may interact with these agents.

Use cautiously in people who have thyroid disorders, or those taking thyroid hormones or medications. RYR may reduce the effectiveness of these agents and may affect thyroid hormone levels.

Use cautiously in people taking ranitidine (Zantac®). RYRE may increase the risk of kidney damage.

Avoid using RYR in children and adolescents under the age of 18, or in pregnant or breastfeeding women. There is a lack of safety information on the use of RYR in these populations.

Avoid if allergic or sensitive to rice, red yeast, its parts, or related members of the yeast family (Monascaceae).

Pregnancy and Breastfeeding

There is a lack of scientific evidence on the use of RYR during pregnancy or breastfeeding.

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